So.
The CSV-60 i bought via German e-bays "kleinanzeigen" showed up at my post office.

Thankfully all in one piece. The amp had survived the trip just fine from the looks of it. So far i´ve just popped the lid off of it and taken a look...and it all looks as it should from where i´m standing at least.

Getting to take a closer look under the hood of it i start to appreciate what the general consensus is as far as that these units can run rather hot.
Difference in space alone inside the amp is..noticable,and as such i presume that can/should be adressed.?

So.
Got a question for you guys. Has any of you actually measured underhood temperatures of a CSV-60?
If so,what kind of temps are we talking?

As for the amplifier in case it will now undergo a restoration as far as replacement of electrolytes and so forth. Atop that i´ll check all the various caps for leakage as a whole asf.

Further someone has installed some sort of relay inside that i still haven´t examined as far as function. It certainly isn´t Braun original and hence will most likely be trashed/taken out of the unit.

The relay turned out to be setup to run vs the outlet for electrostatic speakers. Wires had been cut before me entering the picture,and hence the entire setup was deleted and taken out of the amp.

Anyways.
Got me a couple of hours with the unit on the bench at the shop yesterday.

After a thorough clean/wash with rubbing alcohol and a brush in turn followed by a liberal dose of window cleaner the amp came out looking per above. As a whole unmolested and intact.
As such i set out to reflow the entire amp as far as solder joints. 50yrs is after all 50yrs,and rather safe than sorry.

I then opted to install 1 Ohm "bias resistors" and then hooked the thing to the wall. To my surprise we were all systems go! This thing..was alive and working.

Cleaning it out really made for a difference though,and as a whole and as a general electronics and clean is a good thing. Might sound a little "raw" but i always use various fluids for this. As i´ve got compressed air at the shop..drying it all out is a breeze in turn.
One thing that showed itself as an issue though was the main tower e-lytes of the units. Per "normal" German standard the negative of respective e-lyte is at its housing,and then there´s a large washer being in contact with the housing to which you solder whatever wire needed.
Well,over the years this per definition mechanical contact had come to oxidize a bit..and by simply,for now,removing and cleaning that out the amp came full circle with a breeze.

The EL-504´s installed turned out to still be serviceable. Two pairs from the looks of it,and sure enough the two side showed quite a spread in idle current-albeit being within realms as far as the two pairs being matched vs each other.
However,i felt that setting them up "the other way around" and thereby getting idle current more on the money as far as the two stereo sides were a better option as i do not want one side of the stereo to sound different..i opted to toss the tubes around.
Came close enough in idle current by using the trim pots i guess but will install fresh pots come monday as i get to pick new ones up. The mechanical trim pots by now 50yrs old..yeah well...

What surprised me though,thinking Jens´s post here above,was that upon control not ONE of the onboard caps leaked.
TBH i don´t know how to relate to that as of yet.
The thing here is that most of these CSV units i´ve seen pictures of often show "burning" and miscolouration to the top lid due to heat as a function of service i guess,and the point is that this CSV-60 does not.
Ergo,i presume that it really hasn´t seen all that much use and hence..it might very well be that the condensers are still usable.?

Anyways. Reset bias as stated,and the thing is that bias was set REALLY low for the one side to keep the other side in check.
The "hot" side of it touched down at a mere 30mA or so while the cold side showed like 14mA!
Hence why i swapped the powertubes around,and sure enough...before i had a B+ of approx 380VDC when in 240VAC mode on the voltage selector,and that in turn dropped to approx 358VDC@34mA for both sides.
In short,as the amp was setup the powertrafo wasn´t exactly loaded down to specs.

These units in contrast to the CSV-13 uses germanium diodes for rectification,and not only that but setup per "voltage doubler" as well.
Having a bit of experience with that it is not uncommon for older such setups to become weaker of the yrs which is why i would really like to perform a "load test" of what happens as far as B+ voltage and load increases. Ie,when the amp is asked to produce the wattage.

I just recently modified an old Austrovox guitar amp with about the same setup,just it uses common BY-127 diodes instead,and the difference in voltage drop under heavy load as i "piggy backed" a regular 1N4007 across each BY-127´s back was like night and day.
Without the amp plunged from approx 485VDC to 410VDC under maximum load and with the 1N4007´s in place the same voltage drop was a mere 25VDC under wide open throttle.
Truth be told though i´ve thus far rarely seen that behaviour from the germanium type found in the CSV-60 but....rather safe than sorry i guess..

Come monday i´ll check with my vendor for fresh main e-lytes. Albeit them working i see no reason what so ever to fool around with keeping them in there. As stated,they are 50yrs old and it is time for retirement.
As for the e-lyte for the rectified heater voltage for the preamp i replaced that one right off the bat,and indeed voltage jumped quite a bit. Just as it did for the CSV-13/1 of mine.
Stock they´re of 500uF and that now got replaced by 2200uF. A wise move many a time as it cuts down on any possibility of hum being transduced even more still. Mind you..it MIGHT present a problem doing so as to much capacitance can certainly introduce oscillation. Not so in this case though.

The only part of the CSV-60 that is rectified via selenium is the heater voltage. I plan to replace this with common day n era silicon,but in doing so have measured heater voltage as is.
As has been touched upon previously the heater voltage for the CSV-60 preamp is run in series-in contrast to the CSV-13 where it is hooked in paralell.
As such one has to measure voltage drop across each respective tube to get an accurate reading,and it turns out that with fresh capacitance added and with the voltage selector in 240VAC mode that made this amp at least touch down at a mere 5,7VDC.
The ECC-83´s are rather forgiving as far as heater voltage go,and i expect voltage to go up as i replace the selenium rectifier with silicon,but see no reason to fiddle around with that part more than needed in doing so as we´re at that point FAR from the "roof" as far as heater voltage and ECC-83.

Well. That´s where it´s at at the moment and...i guess we´ll take it from there. This idea of mine of a all "Braun tubeamp surround system" here at home is getting closer to being complete.

Spending yet a few hours with the 60 today i decided to take it home for trials. In fact,me and the Mrs are listening to them both right now and..the whole thing works like a charm.
I´m none the less going to replace the main electrolytics as soon as possible. They ARE no matter what 50+yrs old and there´s no reason what so ever to become cheap here.

I replaced the selenium rectifier for the heater circuit and that made the voltage for the preamp heating jump quite a bit. I now see 6.6VDC across each tube,which TBH is a TAD high why i´m going to implement a ceramic resistor of a few Ohms to make that drop to the set 6,3V.
Point here is that as the 60 uses pin 4+5 vs pin 9 that sets the given limit for the voltage needed. To be compared to how the 13 model is hooked,via pin 4 and 5 respectively.
A small issue to mark with the 60 is that due very intelligent application of the grounding of the system the actual negative pole of the heater-at the rectifier-is at a potential of (now) approx 6,6VDC negative. Ie; -6,6VDC.
This brings a potential vs the tubes "zero" that minimises the risk of interference.
Smart,to say the least.

Indeed the 60 is very well behaved,the little i´ve come to use it thus far (approx 2hrs so far). Just like you Jens i use these amps on a daily basis (surround) why reliability becomes imperative.
On the flipside..when components go belly up it isn´t the end of the world as these unit are very easy to work on.

Temps.
I hear you. So in essence what is said,according to legend only,is that the real issue at hand would be the inner core temp of the transformers.?
Hm.
That..i honestly doubt to a point.
One amp that suffers from this,that is reknown,is the Vox AC-30. Older such often get "imploded" powertransformers. The uniform tell tale then being that they ALWAYS "sweat" before going bust.
You ALWAYS see paraffine and residue melting onto the amp chassis before this happens.
The 60 of mine..hm. Now,as i´ve touched on previously it about works and looks like factory fresh under the hood and around the removable lid. IOW it might be that i´m ill adviced to take to much into account seing what that CSV-60 has NOT seen as far as service.
That a more powerful amplifier by nature will produce more heat stands to reason,that is NOT my beef in this case..
Also granted that the actual amount of "free air" around especially the output transformers is minimised vs the CSV-13...agreed.
That is however NOT the same thing as the transformers are running TO hot.?

Comparing the powertransformer to the CSV-13 ditto though..the 60 model is much more beefy. Not even on the same page,why i strongly doubt that Braun (through Klein&Hummel?) would miscalculate something like that.

Future will tell i gues.

What remains now,here at home,is to either fabricate or purchase a wall suspended shelf system of sorts. My idea is to have one unit set per shelf and hence leave ample room for cooling. idea behind having it wall suspended is to leave the floor free from wires and what have you not (cleaning and so forth).

The old Pioneer receiver in the picture needs to be replaced too,and sorry to say i´d really like to see a receiver that lacks the transistor amplification bit-as i really don´t need it.
The receiver in case is only used for the onboard logics..that´s it. Ie; i use the receivers "preamp out" RCA connections to make it all happen and hence control the whole thing via the receiver remote control.

In the background of the picture you see my Tannoy floor speakers. These are currently complimented by a pair of Tannoy sattelite speakers out back but..i´m going to replace those as well in due time with a set of floor speakers too.
Right now i´m giving thought to a pair of old either Sonab or Carlsson "up sound" speakers from the mid -70´s.
Basically as the "rear" ones don´t really need to be directional IMO.

Well.
That much thus far. Going to snap yet a few pictures as i complete the overhaul completely of the 60 unit. So far...i´m a real happy camper at least!!

(Going to check temps no matter as time permits and will do so even tonight. Through my work with racecars i´ve got a digital pyrometer around the house too.. . No...juuuuuust...no..don´t ask )

The old Pioneer receiver in the picture needs to be replaced too,and sorry to say i´d really like to see a receiver that lacks the transistor amplification bit-as i really don´t need it.

You're my man...

Congratulation, you serviced your CSV60 allready. Well don't worry to much about the CSV60 temperature problem as I believe that the horror tales flooding through the web are related to the first production series. There are of course different objections to the subject - known tube specialists within the Braun forum claim that you should install a PC-Fan to cool down your transformers by air.

BTW yours is a late No. 7819 - close to the CSV60/1 series which was pretty much in balance. Interesting to me is that your anode current reaches 358 VDC. That's overachieving the specs and a bit hot. Mine is working constantantly at 346/348 VDC both channels. I hope you enjoy the CSV60 as much as I do as the sound is an excellent one.

Mine since 35 years (got all of them from my father - new bought in 1965/66)

Well Jens,that sure is a sight for sore eyes!!
Congrats on a really nice looking,and sounding,setup. Look like a million dollars!

Yes. I figured as much that my 60 was a later revision. Some of the caps i removed were stamped 9/64. Kind of tells the story i guess.

Anyways.

Took the 60 with me to the shop again today and replaced everything electrolytic in sight. Add to that that i upped capacitance somewhat for the first hit,and as well for the preamp. The OEM 32uF+32uF cap was replaced by a pair of snap-in of 100uF each.
In turn all of the cathode decoupling ones for the preamp were replaced.

In turn i unbolted the bracket for the powertubes and replaced the two e-lytes for the bias circuit,and here i upped capacitance in a more severe manner,ending up with 2*100uF.
My 60 in turn differed a bit as far as the pentode side of the phaseinverters vs the schematic.
The 2uF cap in the schem for the screen was IRL 470nF. A move that makes the pentode side amplify LESS of the lower frequencys. Replaced that with 1uF e-lytes.
In turn i replaced all of the poly/signal caps while at it. Fresh components all around as far as the PI PCB in short. (Resistors are still stock though)

As for the rectified heater system for the preamp in turn. Remedy for the slightly to high voltage after replacement of the diode setup was simple. I just hooked a 1 Ohm/1w resistor between the rectifier positive and the preamp PCB. Made me end up at 6.3VDC sharp. Done deal.

Amp has followed me home again and..what can i say? It works a friggin million bux worth!
Sound is just mindblowing! It is THAT good. As far as tonal difference vs the CSV-13/1..nah. Not really. Not IMO at least,mind you though...thus far we´re talking "normal" TV volumes in this case.
What´ll happen as i play a vinyl record..remains to be seen.

What i haven´t done to either of the two units is replace any of the poly caps in the preamps.
Maybe one should look into that? Point being that albeit the caps in case doesn´t leak they can sure have drifted a whole lot over the last 50yrs..?

Anyways.
I hope the small tidbits of info i´ve presented can be of use to someone. Like..the silicon swap for rectification of the preamp heaters and how to handle the increased voltage.

Speaking of which. All said and done,and with fresh capacitance in place,i ended up at 359VDC with all 4 powertubes set to 32mA. (mind you this is with 1 Ohm cathode resistors-Ie,it incl anode and screen consumption both)

Oh!
Pulled yet another trick that IS of importance.
None of these amps comply to "the golden rule". That is..that the grounding of the first hit electrolyte should be routed to bridge negative (or centertap for that matter when applicable).

My CSV-60 did NOT comply to "the golden rule",and if you observe the above picture you will see that i´ve routed the two germanium diodes quite different vs stock. Indeed the second diode now runs directly to the solderprong where the second 220uF electrolyte hits the chassis,and...indeed this has made the amplifier very very very silent in idle.

A small,but imperative,little "modification" that needs to be adhered to IMO.

To sum it up.
Absolutely NOTHING is to be let to come between in this case the bridge negative and the grounding of that first series of electrolytes.

Well...that brought a smile to my face Never thought the other way around,that some might have issues with english. Sorry..
Very neat of you to translate though Jens,and to be honest i believe you´re doing a WAY better job than would i ever.
Felt real funny reading my own text in German however.. (´N yes..i guess the Austrovox part can be left out for the sake of argument )

As for the "handwarm"...now this is just none evidence based opinion and what´s more after a mere 1st evening of running in its new enviroment and with fresh parts...
But by using the same measure you do i´m here to tell you that on the outside the CSV-13/1 of mine and the CSV-60 feels about the same temperature.
But..having settled here at home i AM going to bring that pyrometer to it. Got two of them.
First of all one "of the real thing". Ie;a type K element based unit that we use to develop engines.
Then..the second one is simply one of the cheap laser ones.. My thinking here being that you could point the laser through the louvers of the chassis directly onto the transformer cores.

Jens et al.
Servicing these units to become "safe" i guess is one thing,and that is clearly described how to above,a second matter though is...

Have you or any of the others referenced the other capacitors that are onboard? Especially so the preamp and selector switch ones.
As we agree on resistors as well as capacitors DO drift over time and as such i got kind of curious as to how much could be had from basically calling "clean slate" and replacing all of them with the values on the schematic?

In short i wonder how much,if any,that would affect tone of theses CSV units.

Like i´ve touched on above the imperative ones,those that block DC voltage,are all ok from the respect of DC voltage however that in turn says very little for any and all drift as far as total capacitance.

FWIW i for instance measured the two rather highly loaded 100k resistors for each pentode of each ECF-80 for the phaseinverters,and these showed 102k and 112k respectively.
Values close enough to what the schematic calls for not to make for any real difference IMO.
Ergo,i suppose the resistors onboard as a whole can be trusted...which brings us to the capacitor end of it.?

Ok boys.
Here goes.
I´ve thus far only used a simpler pyrometer for the measuring,but at least it is industrial grade.
Please have in mind that this is a type K element,and hence the actual measuring is done at the probe end ONLY.
Thus i placed the probe per Jens´s idea,that is just atop the chassis-at the cooling openings/louvers at the top.

Ok. So that is the actual air temperature right atop the 4pcs of EL-84 powertubes of the CSV-13/1 of mine. Distance from top of chassis to probe approx 5mm and probe end placed in the middle of the 4 tubes in case.

This in turn is the same measurment for the CSV-60 of mine. Same measuring point,same probe and so forth.

This in turn is the temperature measured the same way right atop the powertransformer of the CSV-13/1

...and this the same for the CSV-60

Ambient temperature in the room in case is 22degC. Both amplifiers are placed next to each other approx 60cm above the floor. Humidity in the room i haven´t checked but know from previous that it this time of year when we´ve got a highpressure amounts to about 65% or so.

The findings of mine...are a bit eye opening are they not? Bias for the two machines has been touched on previously,but suffice it to say that both amps have their bias adjusted to within specs for the tubes in question.
Ie; approx 70-80% of maximum rated anode loss in idle.

The first out summary would in my opinion be that the cooling of the CSV-60 is NOT underrated,not in any way.
Also be adviced that both amplifiers were at the time of measure running at rather low volumes. That is...the actual stereo volume in the room was at "TV levels". A fair guesstimate would be 65-70dB or so.

Core and actual bulb temps i have not checked thus far....stay tuned..

Ok.
Just pulled a measure of the bulb temps. Measured at their hottest point,that is in between a tube pair.

The PL-504´s=142degC
The EL-84´s= 158degC

Most likely the 84´s run that much hotter due to smaller bodies vs the power omitted.
Sorry...no pictures. Couldn´t put the probe in place and shoot a photo at the same time,so you´ll have to take my word for it.

The measured powertransformer temp was ~60degC for the core of the CSV-60 and 74degC for the CSV-13/1 (outside of core)
Please be adviced that the CSV-13/1 of mine has been modified on one imperative point,and that is the replacement of the stock selenium diode for a silicon one. That has in turn made the internal B+ voltages jump accordingly,and might very well provide for the increase in powertransformer load and temp.
Then again,it stands to reason that the CSV-13 will be loaded to a higher degree vs the CSV-60 for a given amount of room volume. Ie;the CSV-60 doesn´t have to work as hard to reach the volume given.

The output transformers of the CSV-60 in turn were running at 56degC and the CSV-13/1 at 48degC.
In other words the output transformers of the CSV-13/1 were running cooler at the powerlevels mentioned.

Please be adviced of that. The powerlevels. The temperatures shown are NOT to be regarded as completely conclusive as the powerlevels called for of the two amplifiers were rather low at time of measuring.

None the less,there´s at least part evidence to be found within the results.

Jens.
I believe we can keep sleeping tight and calm. The notion that the CSV-60 would run all that much hotter due to its increased power seems somewhat exaggerated.
If anything i´d state that the underpinnings,amount of room and airflow within the chassis is sufficient to keep both of these amps alive as is. The electronics within in turn,capacitors and what have you not,do NOT run any risk at the temperatures mentioned.
The choice of mine to place the amplifiers main electrolytes at the underside of the chassis in turn would as far as i can gather secure even longer life due to even lower temperatures.

Be adviced that most tubes reference bulb temperature to the other side of 250degC maximum. In that sense neither the PL-504 or the EL-84 are special.

Hi Jesper,
Thanks for sharing your thoughts/findings and pictures concerning temperature and component age in regards to CSV60 and CSV13. To support Gereons efforts translating the core information of this thread, I'll switch to German as I know you are perfectly capable to understand the meaning.

Racing hat geschrieben:

Have you or any of the others referenced the other capacitors that are onboard? Especially so the preamp and selector switch ones.

Like i´ve touched on above the imperative ones,those that block DC voltage,are all ok from the respect of DC voltage however that in turn says very little for any and all drift as far as total capacitance.

Have you or any of the others referenced the other capacitors that are onboard? Especially so the preamp and selector switch ones.As we agree on resistors as well as capacitors DO drift over time and as such i got kind of curious as to how much could be had from basically calling "clean slate" and replacing all of them with the values on the schematic?

The first out summary would in my opinion be that the cooling of the CSV-60 is NOT underrated,not in any way.Also be adviced that both amplifiers were at the time of measure running at rather low volumes. That is...the actual stereo volume in the room was at "TV levels". A fair guesstimate would be 65-70dB or so.

Just pulled a measure of the bulb temps. Measured at their hottest point,that is in between a tube pair.

The PL-504´s=142degCThe EL-84´s= 158degC

Most likely the 84´s run that much hotter due to smaller bodies vs the power omitted.

Sehr interessant!

Racing hat geschrieben:

The measured powertransformer temp was ~60degC for the core of the CSV-60 and 74degC for the CSV-13/1 (outside of core)Please be adviced that the CSV-13/1 of mine has been modified on one imperative point,and that is the replacement of the stock selenium diode for a silicon one. That has in turn made the internal B+ voltages jump accordingly,and might very well provide for the increase in powertransformer load and temp.Then again,it stands to reason that the CSV-13 will be loaded to a higher degree vs the CSV-60 for a given amount of room volume. Ie;the CSV-60 doesn´t have to work as hard to reach the volume given.

02.03., 19:48Spending yet a few hours with the 60 today i decided to take it home for trials. In fact,me and the Mrs are listening to them both right now and..the whole thing works like a charm.I´m none the less going to replace the main electrolytics as soon as possible. They ARE no matter what 50+yrs old and there´s no reason what so ever to become cheap here.

---- nicht übersetzt ----

Racing hat geschrieben:

02.03., 19:48I replaced the selenium rectifier for the heater circuit and that made the voltage for the preamp heating jump quite a bit. I now see 6.6VDC across each tube,which TBH is a TAD high why i´m going to implement a ceramic resistor of a few Ohms to make that drop to the set 6,3V.

02.03., 19:48Point here is that as the 60 uses pin 4+5 vs pin 9 that sets the given limit for the voltage needed. To be compared to how the 13 model is hooked,via pin 4 and 5 respectively.A small issue to mark with the 60 is that due very intelligent application of the grounding of the system the actual negative pole of the heater-at the rectifier-is at a potential of (now) approx 6,6VDC negative. Ie; -6,6VDC.This brings a potential vs the tubes "zero" that minimises the risk of interference.Smart,to say the least.

02.03., 19:48Indeed the 60 is very well behaved,the little i´ve come to use it thus far (approx 2hrs so far). Just like you Jens i use these amps on a daily basis (surround) why reliability becomes imperative.On the flipside..when components go belly up it isn´t the end of the world as these unit are very easy to work on.

02.03., 19:48Temps.I hear you. So in essence what is said,according to legend only,is that the real issue at hand would be the inner core temp of the transformers.?Hm.That..i honestly doubt to a point.One amp that suffers from this,that is reknown,is the Vox AC-30. Older such often get "imploded" powertransformers. The uniform tell tale then being that they ALWAYS "sweat" before going bust.You ALWAYS see paraffine and residue melting onto the amp chassis before this happens.

02.03., 19:48The 60 of mine..hm. Now,as i´ve touched on previously it about works and looks like factory fresh under the hood and around the removable lid. IOW it might be that i´m ill adviced to take to much into account seing what that CSV-60 has NOT seen as far as service.That a more powerful amplifier by nature will produce more heat stands to reason,that is NOT my beef in this case..Also granted that the actual amount of "free air" around especially the output transformers is minimised vs the CSV-13...agreed.That is however NOT the same thing as the transformers are running TO hot.?

02.03., 19:48Comparing the powertransformer to the CSV-13 ditto though..the 60 model is much more beefy. Not even on the same page,why i strongly doubt that Braun (through Klein&Hummel?) would miscalculate something like that.

02.03., 19:48What remains now,here at home,is to either fabricate or purchase a wall suspended shelf system of sorts. My idea is to have one unit set per shelf and hence leave ample room for cooling. idea behind having it wall suspended is to leave the floor free from wires and what have you not (cleaning and so forth).

02.03., 19:48The old Pioneer receiver in the picture needs to be replaced too,and sorry to say i´d really like to see a receiver that lacks the transistor amplification bit-as i really don´t need it.The receiver in case is only used for the onboard logics..that´s it. Ie; i use the receivers "preamp out" RCA connections to make it all happen and hence control the whole thing via the receiver remote control.

In the background of the picture you see my Tannoy floor speakers. These are currently complimented by a pair of Tannoy sattelite speakers out back but..i´m going to replace those as well in due time with a set of floor speakers too.Right now i´m giving thought to a pair of old either Sonab or Carlsson "up sound" speakers from the mid -70´s.Basically as the "rear" ones don´t really need to be directional IMO.

Well.That much thus far. Going to snap yet a few pictures as i complete the overhaul completely of the 60 unit. So far...i´m a real happy camper at least!!

(Going to check temps no matter as time permits and will do so even tonight. Through my work with racecars i´ve got a digital pyrometer around the house too.. . No...juuuuuust...no..don´t ask )

03.03., 23:04Took the 60 with me to the shop again today and replaced everything electrolytic in sight. Add to that that i upped capacitance somewhat for the first hit,and as well for the preamp. The OEM 32uF+32uF cap was replaced by a pair of snap-in of 100uF each.In turn all of the cathode decoupling ones for the preamp were replaced.

In turn i unbolted the bracket for the powertubes and replaced the two e-lytes for the bias circuit,and here i upped capacitance in a more severe manner,ending up with 2*100uF.My 60 in turn differed a bit as far as the pentode side of the phaseinverters vs the schematic.The 2uF cap in the schem for the screen was IRL 470nF. A move that makes the pentode side amplify LESS of the lower frequencys. Replaced that with 1uF e-lytes.In turn i replaced all of the poly/signal caps while at it. Fresh components all around as far as the PI PCB in short. (Resistors are still stock though)

As for the rectified heater system for the preamp in turn. Remedy for the slightly to high voltage after replacement of the diode setup was simple. I just hooked a 1 Ohm/1w resistor between the rectifier positive and the preamp PCB. Made me end up at 6.3VDC sharp. Done deal.

Amp has followed me home again and..what can i say? It works a friggin million bux worth!Sound is just mindblowing! It is THAT good. As far as tonal difference vs the CSV-13/1..nah. Not really. Not IMO at least,mind you though...thus far we´re talking "normal" TV volumes in this case.What´ll happen as i play a vinyl record..remains to be seen.

What i haven´t done to either of the two units is replace any of the poly caps in the preamps.Maybe one should look into that? Point being that albeit the caps in case doesn´t leak they can sure have drifted a whole lot over the last 50yrs..?

Anyways.I hope the small tidbits of info i´ve presented can be of use to someone. Like..the silicon swap for rectification of the preamp heaters and how to handle the increased voltage.

Speaking of which. All said and done,and with fresh capacitance in place,i ended up at 359VDC with all 4 powertubes set to 32mA. (mind you this is with 1 Ohm cathode resistors-Ie,it incl anode and screen consumption both)

Oh!Pulled yet another trick that IS of importance.None of these amps comply to "the golden rule". That is..that the grounding of the first hit electrolyte should be routed to bridge negative (or centertap for that matter when applicable).

My CSV-60 did NOT comply to "the golden rule",and if you observe the above picture you will see that i´ve routed the two germanium diodes quite different vs stock. Indeed the second diode now runs directly to the solderprong where the second 220uF electrolyte hits the chassis,and...indeed this has made the amplifier very very very silent in idle.

A small,but imperative,little "modification" that needs to be adhered to IMO.

To sum it up.Absolutely NOTHING is to be let to come between in this case the bridge negative and the grounding of that first series of electrolytes.

Racing hat geschrieben:

04.03., 03:47Well...that brought a smile to my faceNever thought the other way around,that some might have issues with english. Sorry..Very neat of you to translate though Jens,and to be honest i believe you´re doing a WAY better job than would i ever.Felt real funny reading my own text in German however..(´N yes..i guess the Austrovox part can be left out for the sake of argument )

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Racing hat geschrieben:

04.03., 03:47As for the "handwarm"...now this is just none evidence based opinion and what´s more after a mere 1st evening of running in its new enviroment and with fresh parts...But by using the same measure you do i´m here to tell you that on the outside the CSV-13/1 of mine and the CSV-60 feels about the same temperature.But..having settled here at home i AM going to bring that pyrometer to it. Got two of them.First of all one "of the real thing". Ie;a type K element based unit that we use to develop engines.Then..the second one is simply one of the cheap laser ones.. My thinking here being that you could point the laser through the louvers of the chassis directly onto the transformer cores.